Tree step



FIG. 1 is a perspective view of a tree step showing my new design;

FIG. 2 is a left side view thereof and is the mirror image of the right side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a front view thereof; and,

FIG. 6 is a back view thereof. 

The ornamental design for a tree step, as shown and described. 